Muira puama is the wood derived from Liriosma ovata Miers, Oleaceae, also known as Acanthea virilis Wehmer, Acanthaceae, a shrub or small tree found in the region around the Amazon and Orinoco river basins. The roots and woody stems of muira puama are popularly known for their astringent quality as a treatment for diarrhea. R. C. Wren, Potter's New Cyclopaedia of Botanical Preparations (1988). In addition, muira puama is included in a number of commercial formulations that purport to contain aphrodisiac activity. Clarence Meyer, Herbal Aphrodisiacs from World Sources (1986) (hereinafter "Meyer"). Miller has recognized that muira puama contains an unidentified resin that has a strong stimulating effect upon the human central nervous system and, assertedly, the libido. R. A. Miller, The Magical and Ritual Use of Aphrodisiacs (1985) (hereinafter "Miller", which is incorporated by reference herein). Astringency and sexual stimulation are believed to be the only reported activities derived from muira puama.
The muira puama root is commercially available and it usually occurs as light-brown to pink-brown hard, tough, fibrous, woody splinters. The root is odorless and has a slightly astringent taste.
The chemical constituents of muira puama are not well characterized, but it has been reported that muirapaumine, esters of benzoic acid, lupeol, and phytosterols are present. Merck Index (11th Ed. 1989); Auterhoff and Pankow, 301 Arch. Pharm. (Weinheim) 481 (1968); Auterhoff and Parkow, 302 Arch. Pharm. (Weinheim) 209 (1969); A. Heinz, Drogenkunos (1975). The root's supposed aphrodisiac activity is thought to reside in an aromatic resin of unknown composition. W. H. Lee & L. L. Lee, Herbal Love Potions (1991); G. W. Griffin, Aphrodisiacs for Men (1991) (hereinafter "Griffin"). Although it has been claimed that the active ingredient is testosterone, this claim has not been substantiated by chemical analyses. T. Fahey, Steroid Alternative Handbook (1993). Even if this claim were substantiated, it could not be the source of the root's purported aphrodisiac activity because oral ingestion of the root would cause any such testosterone to be rapidly degraded by the liver.
The aromatic resin is not considered to be sufficiently active when muira puama is ingested in powder form. The resin is not water soluble, therefore it cannot be extracted into water. Miller (1985); Meyer (1986); Griffin (1991). In order to prepare active quantities of muira puama, the root or bark material must be extracted with alcohol. Miller (1985) describes a typical "home use" extraction procedure consisting of mixing the powdered root with boiling vodka and straining the resulting extract before consumption. Alternatively, the resin may be extracted from the root or bark with hot isopropanol, or other alcohol, whereafter the extract is strained and evaporated. A small portion of the residue is then dissolved in the mouth to obtain the purported sexual stimulation.
Up until the present invention, muira puama has not been reported as having any use for the treatment of obesity or for increasing lean muscle mass.
There is a great need for a method of reducing body fat. Excess body fat is a known risk to good health. Obesity, or excess body fat, is an independent heart disease risk equal to that of smoking, high blood pressure, and elevated plasma lipids. The National Institutes of Health have found that obesity should be viewed as a disease. In an eight year study which included over 100,000 female nurses, the NIH found that even subjects that were slightly overweight were at an increased risk for myocardial infarction and coronary artery disease. Subjects of average weight were found to experience about 30% more heart attacks than the thinnest subjects. The risk of heart attacks for those subjects that were moderately overweight was 80% higher than that for the thin subjects. J. E. Manson et al., New England J. Med. 822 (1990).
Obesity is also associated with impairment of cardiac function due to an increase in the heart's mechanical workload, hypertension, stroke, diabetes, renal disease, gallbladder disease, pulmonary disease, problems in the administration of anesthesia during surgery, osteoarthritis, degenerative joint disease, gout, abnormal plasma lipid and lipoprotein concentration, menstrual irregularities, and psychological problems. S. W. Rabkin, et al., 39 Am. J. Cardiology 452 (1977).
Many factors may predispose a person to excessive body fat, which may be quantified as a percentage of total weight. These include: eating patterns, environment, psychological factors such as body image, and biochemical differences related to resting metabolic rate, dietary-induced thermogenesis, levels of spontaneous activity, basal temperature, levels of cellular adenosine triphosphatase, lipoprotein lipase and other enzymes, and metabolically active brown adipose tissue. K. D. Brownell & J. P. Foreyt, Handbook of Eating Disorders (1986); R. T. Frankel and M-W Yang, Obesity and Weight Control (1988).
As people age, the body fat percentage of the body increases while the important lean muscle mass decreases. K. Imamura et al., 33 J. Gerontology 678 (1983). The maintenance of lean muscle mass is considered extremely important as the loss of muscle strength is directly related to limited mobility and physical performance as well as to increases in the incidence of accidents suffered by the elderly. R. Goldman & M. Bockstein, Physiology and Pathology of Aging (1975). In addition, a number of other muscle-wasting disease conditions exist, such as late stage cancer or AIDS, in which compositions to improve lean muscle mass would be desirable.
Substances and techniques believed or reported to increase lean muscle mass and thereby decrease the percentage of body fat include alcohol, amphetamines, epinephrine, aspartates, red cell reinfusion, caffeine, protein, phosphates, oxygen-rich breathing mixtures, gelatin, lecithin, wheat-germ oil, vitamins, herbs such as ginseng, sugar, minerals, ionized air, music, hypnosis, marijuana, cocaine, anabolic steroids, and human growth hormone. F. R. Hatfield, Ultimate Sports Nutrition (1987). Few, if any, of these substances or techniques have been scientifically proven to be of any value, and a number, such as anabolic steroids, amphetamines, and illicit compounds, potentially have dangerous side effects.
As an example, anabolic steroids have become popular among many professional and amateur athletes. Not only have few studies documented any significant positive effects from these drugs, but they have severe adverse side effects including hirsutism, hair loss, sterility, liver disease, cancer induction, decrease in serum HDL, and development of a hostile/aggressive personality. E. E. Yesalis, Anabolic Steroids in Sport and Exercise (1993).
The present invention provides methods and compositions for reducing total body fat percentage while increasing lean muscle mass, and for decreasing blood cholesterol levels, by ingestion of an extract derived from muira puama. This extract does not have the severe side effects present in other known treatments.